Directory

Open Source Packages

Libraries, frameworks, tools, and SDKs used by the apps in this directory — scored the same way as the apps themselves.

5929 packages

All Packages

78Health
Tool npm

eslint-plugin-import

ESLint rules that validate ES module import/export syntax and catch broken paths before they hit your build.

5,947
MIT
Used by 116
77Health
Library npm

user-event

Simulates the full sequence of real browser events so Testing Library tests behave the way an actual user does.

2,330
MIT
Used by 116
81Health
Library PyPI

Requests

The elegant, human-friendly HTTP library that made Python's most-used API for talking to the web.

54,353
Apache 2.0
Used by 112
95Health
SDK npm

Sentry JavaScript (@sentry/browser)

The official Sentry SDK for capturing errors, performance traces, and session replays in browser JavaScript apps.

8,745
MIT
Used by 110
82Health
Library npm

i18next

The internationalization framework for JavaScript, with zero runtime dependencies and a pluggable ecosystem for every environment.

8,637
MIT
Used by 110
90Health
Library npm

sharp

High-performance Node.js image processing powered by libvips, built for fast resizing and format conversion.

32,726
Apache 2.0
Used by 109
92Health
Library npm

AI SDK

Provider-agnostic TypeScript toolkit for building AI apps and agents with any LLM.

26,955
Apache 2.0
Used by 105
93Health
Library PyPI

Pydantic

Data validation and settings management using Python type hints, backed by a Rust core.

28,891
MIT
Used by 104
96Health
Framework PyPI

pytest

The Python testing framework that makes writing small tests easy and scales to complex functional test suites.

14,543
MIT
Used by 100
72Health
Library npm

Chalk

The most popular Node.js library for styling terminal string output with ANSI colors.

23,319
MIT
Used by 98
96Health
Library npm

OpenTelemetry JavaScript (@opentelemetry/api)

Vendor-neutral tracing, metrics, and context API that libraries and apps instrument once, so any OpenTelemetry-compatible backend can consume it.

3,479
Apache 2.0
Used by 91
95Health
Tool npm

Storybook

The industry-standard workshop for building, documenting, and testing UI components in isolation, across every major frontend framework.

91,163
MIT
Used by 90
97Health
Tool npm

webpack

A static module bundler that builds a dependency graph of your project's modules and packages them into optimized browser bundles

65,963
MIT
Used by 90
67Health
Library npm

DOM Testing Library

Simple, framework-agnostic DOM query utilities that test your UI the way real users interact with it.

3,335
MIT
Used by 87
56Health
Library PyPI

HTTPX

A next-generation HTTP client for Python with sync, async, and HTTP/2 support

15,517
BSD 3
Used by 86
95Health
SDK npm

OpenAI

The official Node.js/TypeScript client for the OpenAI API, auto-generated from OpenAI's own OpenAPI spec.

11,192
Apache 2.0
Used by 86
64Health
Library npm

fs-extra

Drop-in replacement for Node's fs module adding copy, remove, mkdirs, and JSON helpers with native promise support.

9,590
MIT
Used by 84
91Health
Tool PyPI

Uvicorn

A lightning-fast ASGI server for Python, built on uvloop and httptools.

10,993
BSD 3
Used by 83
90Health
Library npm

TanStack Virtual (React)

Headless React hook for virtualizing massive lists, grids, and tables at 60FPS.

7,123
MIT
Used by 83
91Health
Library npm

Tiptap Core

Headless, framework-agnostic rich text editor toolkit built on ProseMirror

38,558
MIT
Used by 82
95Health
Library PyPI

NumPy

The fundamental N-dimensional array library powering Python's scientific computing stack.

32,864
BSD 3
Used by 82
92Health
Library npm

ioredis

A robust, full-featured Redis client for Node.js with built-in Cluster, Sentinel, and TypeScript support.

15,343
MIT
Used by 81
55Health
Library npm

tslib

The runtime library that houses TypeScript's compiler helper functions so your emitted code stays small.

1,343
Other
Used by 81
92Health
Library npm

Mermaid

Generate flowcharts, sequence diagrams, and 20+ other diagram types from markdown-like text

90,450
MIT
Used by 80

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